Author/Authors :
Neshati Rad، Mokhtar نويسنده Department of Water Engineering, Faculty of Agriculture, University of Urmia, Urmia , , Majnooni-Heris، Abolfazl نويسنده Department of Water Engineering, Faculty of Agriculture, University of Tabriz, Tabriz, Iran , , Besharat، Sina نويسنده Department of Water Engineering, Faculty of Agriculture, University of Urmia, Urmia , , Jabbari، Anahita نويسنده Department of Water Engineering, Faculty of Agriculture, University of Urmia, Urmia ,
Abstract :
ABSTRACT: Prediction of crop evapotranspiration is important in irrigation scheduling and water resource management. The values of potential crop evapotranspiration are estimated by reference crop evapotranspiration (ETo) and crop coefficient. In this research, maize evapotranspiration (ETc) was measured by lysimeter in agricultural fieldsofKarkajlocatedin Tabriz University and were measured by water balance method in Bajgah Agricultural Experiment Station of Shiraz University. The values of ETc were estimated by considering ETovalues and dual crop coefficient method. The values of ETo were estimated by using pan evaporation and Penman-Monteithmethods. The measured seasonal values of ETc in agricultural fieldsofKarkaj and Bajgahin first and second year were 829, 814 and 818 mm, respectively. The estimated seasonal values of ETc by considering the estimated values of ETo by Penman-Monteithmethod in agricultural fields of the Karkaj and Bajgahinthefirst and second experimental years were723, 693and 700 mm, respectively. The estimated seasonal values of ETcby considering the estimated values of ETofrom pan-evaporation method in agricultural fields of the Karkajwas 852 mm and in the Bajgahwere 736 and 796 mmin first and second experimental years, respectively. The results confirmed that the calculation of ETo by considering pan-evaporation in dual crop coefficientmethod, improved the accuracyof crop evapotranspiration estimation.
